Cast-metal pipe.



PATENTED NOV. 20, 1906.

R. P. BARNSTEAD. GAST METAL HPB. APPLIUATION FILED JAN. 21 190s.

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Nov. 20, 1906.

Application filed January Z1, 1905. Serial No. 242,057.

T0 all whom it may con/cern.'

Be it known that I, ROBERT P. BARNsTEAD, a citizen of the United States, and a resident of Boston, county of Suffolk, State of Massachusetts, have invented certain new and useful Improvements in Cast -Metal Pipes, of

which the following is a full, clear, and exact description. n

In the construction of sewer-pipes it is customary to form the same in sections, each section having one end enlarged to receive the smaller end of the next section, melted lead being poured into the joint to render the same gas and water tight. In sewer-pipes extending upward to considerable heights, and especia ly where much hot water is caused to escape through them, as in large hospitals, such pipes are subjected to not a little expansion and contraction, and as certain of the sections are held quite firmly at different points there is more or less longitudinal movement at many of the joints, the lead packing being incapable of resisting the same. Consequently leaks are not infrequent at certain of said joints through which mephitic gases and even waste water will escape and threaten the life and health of the inmates of the building.

The object of this invention is the construction of such pipe-sections that shall be inca able of working loose from each other, and lience to be depended upon for absolute security from all danger of sewer-gas and other waste elements.

In carrying out my invention I prefer to form the pipe-sections of cast metal, as iron, and to provide both the male and female ends of the sections with integral locking projections, by means of which the said sections are made rigid one with the other in order that the sealing function may be the only one required of the lead packing.

The drawing forming part of this specification shows a plurality of pipe-sections embodying my invention, the larger part being in central longitudinal section.

The reference-numeral l designates the body of each pipe-section, 2 the enlarged or female end thereof, and 3 the male end. The inner diameter of the female end is made substantially larger than the outer diameter of the male end in order to allow ample space for the lead packing 8 and also for the lockino' devices, to be hereinafter described. Within said female end is formed near its upper end an annular groove 7 for the purpose of receiving a corresponding portion of the lead packing and to thereby aid in preventing the accidental displacement of the latter. Close to the end 3 are formed two or more separate helical threads integral with the pipe, with the extremity of one terminating in the same longitudinal plane with vthe end -of the other. As shown in the drawing7 the end of the thread 5 is directly below the end of the thread 5a in subrtantially the same formed with two or more separate helical,

threads 6 6, fitted to engage the threads 5a.

One pipe-section having been screwed down into another until the end 3 is firmly seated upon the fiat shoulder 4 and the contacting surfaces 3 and 4 are substantially impervious to the passage of a fluid, but articularly of melted lead, sufficient of the atter is poured into the annular space about the end 3 to partially fill the same. Then such lead is firmly tamped to render impossible any escape of gases and the remainder of the space filled with the same material, such melted metal flowing into and filling the groove 7 above described, and `thereby keeping this latter applied lead from working out in any possible way. Thus made the pipe-sections are locked against the slightest longitudinal displacement by the interlocking projections 5 6, while the lead packing provides an unalterably impervious seal thereto.

The reason why I forni each helical thread 5 and 6 not more than half a circumference in length is twofold: First, a single thread extending an entire circumference of the pipe would necessitate an entire turn on the part of a pipe-section in screwing it into another. As it is, a half-turn or even less is sufficient for the purpose. Second, by shortening the threads the melted lead is given a much shorter passage through which to pass from the openings between the thread ends to the extremity of the pipe end 3 and will therefore reach its journeys end with less loss of heat and in a better condition to thoroughly fill and occupy every crevice. I do not restrict myself, however, to such lengths of the helical threads 5 and 6, either in the direction of making them considerably longer or a great deal shorter until they compose merely lugs o n the one section engaging lugs or threads on the other.

The parts designated by the reference-numeral 9 are simply the customary strength en- IIO ing-rims for the female ends 2 to support them against breaka e.

Although I have (Iescribed the packing 8 as composed of lead melted and poured into place, I do not restrict myself thereto, as my construction of the interlocking sections binds the same so firmly together that any kind of packing will serve the purpose sub-v stantially as well, as rubber or cement. Furthermore, my construction is the only one which will ermit of soil-pipes of considerable size being ocated in unsupported horizontal positions when formed in sections. The weight of the pipe when made in the custom ary manner will cause the lead packing to gradually yield until the sections acquire a ecided curve and the joints are leaking badly. With my interlocking devices, however, the pipe-sections are practically made into one rigid length capable of sustaining itself unaffected in either vertical, horizontal, or other positions.

What I claim as my invention, and for which I desire Letters Patent, is as follows, to wit:

1. Pipe-sections having each a female end provided with a plurality of helical threads each extending a semicircumference therein, and a male end formed With locking projece tions tted to said threads, and provided with a packing fillin the spaces between each male and female en.

2. Pipe-sections having each a female end provided. with a plurality of helical threads each extending a semicircumference therein, and a male end formed with corresponding helical threads fitted to those of the female end, and a fusible packing filling the space about said threads and between said ends.

In testimony that I claim the foregoing invention I have hereunto set my hand this 19th day of January, 1905.

ROBERT `I). BARNSTEAD.

Witnesses:

FRED G. TILTON, A. B. UPHAM. 

